Why Do Biologists Use Specific Dyes for Different Cell Types?

[FrancisZ]

Quick Questions...


Why do Biologists use different dyes for different slide samples?

I've heard of iodine, and methylene blue being used for plant and animal cells respectively.
Does it matter? And how come?


Does it have to do with the reaction? Would Iodine dissolve an animal cell like Cheek cells if you used it instead of Methylene blue?

 

[Bacat]

Different stains are used to highlight different structures in the cell. By using the appropriate stain you could improve visibility of cell components depending on their make-up. If I remember right methylene blue is most useful for studying the nuclei of cells. Iodine is good for tagging starches, among other things. Using the right stain will improve the quality of information the biologist gets.

Microbiologists also use a gram-negative and a gram-positive stain to identify which class of bacteria they have. In general, gram-positive bacteria are not harmful but gram-negative bacteria are (to humans), so this is a good way for us to determine which is which. The stain selectively adheres to different types of cell-walls.

In modern days biologists often use fluorescent markers also. Here, the color of the dye is defined by the molecules of dye themselves. The biologist can excite the fluorescent dyes selectively using specific wavelengths of light and thus pick out which parts of the cell have been tagged. This is particularly useful for in vitro (live) microscopy where a biologist might want to study how certain markers move within a cell. The dyes do not harm the cell and yet provide useful information.

 

[Blueshift5]

Biologists use different dyes for different slide samples because each dye has specific properties that make it more suitable for certain types of cells or tissues. For example, iodine is commonly used to stain plant cells because it reacts with starch, a carbohydrate found in plant cells, making it easier to visualize under a microscope. Methylene blue, on the other hand, is commonly used to stain animal cells because it binds to the DNA and other acidic components of the cell, making it easier to distinguish individual structures within the cell.

It does matter which dye is used because each dye has a specific purpose and will react differently with different types of cells. Using the wrong dye could result in inaccurate or unclear results.

As for your question about iodine dissolving an animal cell, it is unlikely as iodine is typically used in a diluted form and does not have strong dissolving properties. However, it may interfere with the staining process and make it difficult to visualize the cell structures. This is why it is important to use the appropriate dye for each type of cell or tissue.